I am trying to get the runtime of the following code using the clock_gettime function. However when I am running the code I am receiving a time of 0.0000 every time it runs. I have output the start and stop time individually also and I am receiving the exact same answer.
struct timespec start, stop; double accum; if( clock_gettime( CLOCK_REALTIME, &start) == -1 ) { perror( "clock gettime" ); exit( EXIT_FAILURE ); } int src = 1, final_ret = 0; for (int t = 0; t < rows - 1; t += pyramid_height) { int temp = src; src = final_ret; final_ret = temp; // Calculate this for the kernel argument... int arg0 = MIN(pyramid_height, rows-t-1); int theHalo = HALO; // Set the kernel arguments. clSetKernelArg(cl.kernel(kn), 0, sizeof(cl_int), (void*) &arg0); clSetKernelArg(cl.kernel(kn), 1, sizeof(cl_mem), (void*) &d_gpuWall); clSetKernelArg(cl.kernel(kn), 2, sizeof(cl_mem), (void*) &d_gpuResult[src]); clSetKernelArg(cl.kernel(kn), 3, sizeof(cl_mem), (void*) &d_gpuResult[final_ret]); clSetKernelArg(cl.kernel(kn), 4, sizeof(cl_int), (void*) &cols); clSetKernelArg(cl.kernel(kn), 5, sizeof(cl_int), (void*) &rows); clSetKernelArg(cl.kernel(kn), 6, sizeof(cl_int), (void*) &t); clSetKernelArg(cl.kernel(kn), 7, sizeof(cl_int), (void*) &borderCols); clSetKernelArg(cl.kernel(kn), 8, sizeof(cl_int), (void*) &theHalo); clSetKernelArg(cl.kernel(kn), 9, sizeof(cl_int) * (cl.localSize()), 0); clSetKernelArg(cl.kernel(kn), 10, sizeof(cl_int) * (cl.localSize()), 0); clSetKernelArg(cl.kernel(kn), 11, sizeof(cl_mem), (void*) &d_outputBuffer); cl.launch(kn); } if( clock_gettime( CLOCK_REALTIME, &stop) == -1 ) { perror( "clock gettime" ); exit( EXIT_FAILURE ); } printf( "%lf\n", stop.tv_sec ); printf( "%lf\n", start.tv_sec ); accum = ( stop.tv_sec - start.tv_sec ) + ( stop.tv_nsec - start.tv_nsec ) / BILLION; printf( "%lf\n", accum ); Any advice on what I'm doing wrong is much appreciated
